Effect of Matter Density in the Evolution of the Universe

Total Page:16

File Type:pdf, Size:1020Kb

Effect of Matter Density in the Evolution of the Universe Effect of Matter Density in the Evolution of the Universe Kara Farnsworth, Christina King, Ryan Price University of Arizona The formation, expansion and evolution of the structure of the universe are determined by the ratio of varying densities of the matter components that comprise it. Using the Friedmann Equation to describe the evolution of the universe, we investigate the properties of the each component of the universe to determine the role played by each in the evolution of the universe. Using numerical methods, the Friedmann Equation was solved using various parameters for the densities. From the computations it was found that the age of the universe is mostly dependent upon the dark energy and matter components of the universe while the radiation density has less effect. Introduction Currently, most scientists believe that the universe is approximately 13.4 billion years old. There are multiple approaches to measuring the age of the universe. One approach is the observation of cosmic microwave background or CMB. By measuring the CMB scientists have studied the radiation of the universe as far back in time as the Big Bang1. The universe is so large that when scientists observe far away materials and radiation, they are in fact looking back in time. This is due to the time taken for light to travel from these places to Earth1. Therefore, by using the amount of radiation of the material to find the distance to these sources, scientists can estimate the age of the universe. Another method used to find the age of the universe is the rate of expansion of the elements in it. The “discovery that distant galaxies are all receding from us with velocities that are proportional to their distances” shows that all the galaxies came from one single point and expanded at the same time2. By measuring the rate of expansion, assuming that it is constant, and how far apart the objects are today, scientists can estimate the amount of time needed for these astronomical bodies to become as far apart as they are currently3. Using this method the universe is roughly 14 billion years3 old. The third method is finding specific microwaves from the beginning of the universe and using them to calculate the universe’s age. The “detection of the 1 Barkana, Rennan. "The First Stars in the Universe and Cosmic Reionization." 2 Van Den Bergh, Sidney. "Size and Age of the Universe." 3 Gould, Adam. "IPS Offical Statement on the Ancient Age of the Earth and Universe." Farnsworth, King, Price 2 3 K microwave background by Penzias and Wilson, which represents the red shifted radiation of the primeval fireball” provides evidence of a single starting point and also evidence for the Big Bang, which many scientists believe is how the universe started4. Despite how the universe started, most agree that it has a definite beginning. There is also other evidence that makes scientists think that there is a single beginning to the universe. The universe could also be “open”, in which there would be no beginning and it would be indefinitely old. However, there is not as much evidence supporting this argument. Though these methods give an approximate age of the universe, the most exact method is solving Friedmann’s equation. Aleksandr Friedmann was a Russian physicist and mathematician who, after studying Einstein’s Friedmann derived his equation using the Einstein field equations, assuming “a homogeneous and isotropic universe” 5 and wrote the paper On the curvature of Space to Zeitschrift für Physik. In this paper Friedmann proposed that “the radius of curvature of the universe can be either an increasing or a periodic function of time”6 and derived his famous equation. Assumptions and Equations While comparing the red-shifts and the distances of different objects in the universe, Edwin Hubble realized there was a relationship between the distance of the object and its velocity away from us. From this information, Hubble concluded the universe is expanding. He expressed this expansion using his “Hubble constant”. v = Hd (1) Where H is the Hubble constant. With further observation, Hubble realized that the universe is not only expanding, but also accelerating. This means ! that the Hubble constant is not actually constant. If the distance between objects in the universe is represented as R(t), and the distance between objects currently is represented as R0, then the ratio between them,α, is R(t) !(t) = (2) R0 4 Van Den Bergh, Sidney. "Size and Age of the Universe." 5 Weisstein, Eric W. "Friedmann-Lemaitre Cosmological Model." 6 "Aleksandr Aleksandrovich Friedmann." Farnsworth, King, Price 3 Where α (0) = 1. Then the Hubble constant can be written in terms of α. 2 1 # d" & H = % ( (3) " $ dt ' By taking the inverse of the present Hubble “constant”, H0, a rough estimate of the age of the universe can be found. ! *1 1 $ 1000m 31536000s 1Mpc ' 10 = t0 " & 71# # # 22 ) =1.34 *10 yrs (4) H0 % 1km 1yr 3*10 m( Or the universe is approximately 13.4 billion years old. But since the Hubble constant changes with time, this number is only an approximation. The real ! age of the universe is better calculated using the Friedmann equation. The Friedmann equation includes the Hubble constant to give a much more accurate age of the universe. 2 1 # d" & 8)G kc 2 % ( = (*r + *m + *d ) + 2 2 (5) " $ dt ' 3 R0 " In this equation, G is the gravitational constant = 6.67*10-11Nm2/kg2, ρr is the radiation density of the universe, ρm is the matter density of the universe, ! and ρd is the dark energy density of the universe. The variable k is the curvature parameter of the universe and can be either -1, 0, or 1 for a closed, flat, and open universe respectively. R0 as stated before is the separation distance between objects in the universe presently, and c is the speed of light = 3*108 m/s. The various densities of the universe also vary with time. " " (t) = r0 (6) r # 4 "m0 "m (t) = 3 (7) ! # (t) (8) "d = "d 0 ! These densities are usually expressed in terms of the critical density, ρc. ! 3H 2 " = (9) c 8#G ! Farnsworth, King, Price 4 In order to make equation 5 dimensionless, the various densities are better expressed as a ratio of the critical density. The ratios of the density of the universe vs. the critical density are expressed as Ω. # #r (t) r0 "r (t) = = 4 (10) #c #c$ # #m (t) m0 "m (t) = = 3 (11) ! #c #c$ # #d (t) d 0 "d (t) = = (12) ! #c #c " = "r + "m + "d (13) ! In order for the Friedmann equation to work, there must be a relationship between k (the curvature parameter) and Ω. When Ω < 1, k = -1. When Ω = 1, ! k = 0. When Ω > 1, k =1. Taking these parameters into account, the age of the universe can be found for an open, flat or closed universe. Substituting equations 9, 10, 11 and 12 into equation 5 gives: 2 d# !4 !3 kc = H# (" r# + " m# + " d )! 2 (14) dt R0 This equation was put into a program and be solved for α(t) using the Runge- Kutta method. Depending on the type of material included in our universe, the universe will have different predicted ages. Research has found that for the universe Hubble’s constant is about 71 km/s/Mpc, r=3x10-5, m=0.27, d=0.73. Using numerical solutions, the age of the universe was investigated for variable values of which were greater than or less than 1. It is important, however, to understand the equations we will be using to find the age of the universe. The equations used for our research cannot be solved analytically for all solutions. However, using numerical methods, the Friedmann equation, equation 14, can be solved for various density parameters and scenarios. To solve the Friedmann equation numerically, the 4th-order Runge-Kutta method was used. The Runge-Kutta method “propagate(s) a solution over an interval by combining the information from several Euler-style steps (each involving one evaluation of the right-hand f’s), and then using the information obtained to match a Taylor series expansion up to some higher Farnsworth, King, Price 5 order.” 7 The Runge-Kutta method works by using initial values say xn and yn and wanting to find yn+1. The following algorithm6 was used to numerically solve the Friedmann equation: k1 = h ! f (xn , yn ) ' h k1 $ k2 = h ! f % xn + , yn + " & 2 2 # ' h k2 $ k3 = h ! f % xn + , yn + " & 2 2 # k4 = h ! f (xn + h, yn + k3 ) k k k k y = y + 1 + 2 + 3 + 4 n+1 n 6 3 3 6 Where h is the step size and f(x,y) is the differential equation: the Friedmann equation. Using a given set of initial parameters, the algorithm was able to produce a plot of the value of versus the time t. For each scenario that is numerically solved and plotted, the age of the universe can be inferred from the point where equals zero on the t axis. Verification of numerical method The simplest way to verify the numerical method to solve the Friedmann Equation is to look at specific scenarios, formulate their outcomes, and compare them to the numerical results with similar parameters. To do this, one starts with a variation of the Friedmann Equation: & kc 2 # H 2 = H 2 $( a '4 + ( a '3 + ( ' ! (15) 0 $ r m d 2 2 ! % H 0 a " Where H is the Hubble parameter described in equation 3. Using this form, there are three specific cases that can be solved analytically.
Recommended publications
  • The Age of the Universe Transcript
    The Age of the Universe Transcript Date: Wednesday, 6 February 2013 - 1:00PM Location: Museum of London 6 February 2013 The Age of The Universe Professor Carolin Crawford Introduction The idea that the Universe might have an age is a relatively new concept, one that became recognised only during the past century. Even as it became understood that individual objects, such as stars, have finite lives surrounded by a birth and an end, the encompassing cosmos was always regarded as a static and eternal framework. The change in our thinking has underpinned cosmology, the science concerned with the structure and the evolution of the Universe as a whole. Before we turn to the whole cosmos then, let us start our story nearer to home, with the difficulty of solving what might appear a simpler problem, determining the age of the Earth. Age of the Earth The fact that our planet has evolved at all arose predominantly from the work of 19th century geologists, and in particular, the understanding of how sedimentary rocks had been set down as an accumulation of layers over extraordinarily long periods of time. The remains of creatures trapped in these layers as fossils clearly did not resemble any currently living, but there was disagreement about how long a time had passed since they had died. The cooling earth The first attempt to age the Earth based on physics rather than geology came from Lord Kelvin at the end of the 19th Century. Assuming that the whole planet would have started from a completely molten state, he then calculated how long it would take for the surface layers of Earth to cool to their present temperature.
    [Show full text]
  • Hubble's Law and the Expanding Universe
    COMMENTARY COMMENTARY Hubble’s Law and the expanding universe Neta A. Bahcall1 the expansion rate is constant in all direc- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 tions at any given time, this rate changes with time throughout the life of the uni- verse. When expressed as a function of cos- In one of the most famous classic papers presented the observational evidence for one H t in the annals of science, Edwin Hubble’s of science’s greatest discoveries—the expand- mic time, ( ), it is known as the Hubble 1929 PNAS article on the observed relation inguniverse.Hubbleshowedthatgalaxiesare Parameter. The expansion rate at the pres- between distance and recession velocity of receding away from us with a velocity that is ent time, Ho, is about 70 km/s/Mpc (where 1 Mpc = 106 parsec = 3.26 × 106 light-y). galaxies—the Hubble Law—unveiled the proportional to their distance from us: more The inverse of the Hubble Constant is the expanding universe and forever changed our distant galaxies recede faster than nearby gal- Hubble Time, tH = d/v = 1/H ; it reflects understanding of the cosmos. It inaugurated axies. Hubble’s classic graph of the observed o the time since a linear cosmic expansion has the field of observational cosmology that has velocity vs. distance for nearby galaxies is begun (extrapolating a linear Hubble Law uncovered an amazingly vast universe that presented in Fig. 1; this graph has become back to time t = 0); it is thus related to has been expanding and evolving for 14 bil- a scientific landmark that is regularly repro- the age of the Universe from the Big-Bang lion years and contains dark matter, dark duced in astronomy textbooks.
    [Show full text]
  • The Reionization of Cosmic Hydrogen by the First Galaxies Abstract 1
    David Goodstein’s Cosmology Book The Reionization of Cosmic Hydrogen by the First Galaxies Abraham Loeb Department of Astronomy, Harvard University, 60 Garden St., Cambridge MA, 02138 Abstract Cosmology is by now a mature experimental science. We are privileged to live at a time when the story of genesis (how the Universe started and developed) can be critically explored by direct observations. Looking deep into the Universe through powerful telescopes, we can see images of the Universe when it was younger because of the finite time it takes light to travel to us from distant sources. Existing data sets include an image of the Universe when it was 0.4 million years old (in the form of the cosmic microwave background), as well as images of individual galaxies when the Universe was older than a billion years. But there is a serious challenge: in between these two epochs was a period when the Universe was dark, stars had not yet formed, and the cosmic microwave background no longer traced the distribution of matter. And this is precisely the most interesting period, when the primordial soup evolved into the rich zoo of objects we now see. The observers are moving ahead along several fronts. The first involves the construction of large infrared telescopes on the ground and in space, that will provide us with new photos of the first galaxies. Current plans include ground-based telescopes which are 24-42 meter in diameter, and NASA’s successor to the Hubble Space Telescope, called the James Webb Space Telescope. In addition, several observational groups around the globe are constructing radio arrays that will be capable of mapping the three-dimensional distribution of cosmic hydrogen in the infant Universe.
    [Show full text]
  • Galaxies at High Redshift Mauro Giavalisco
    eaa.iop.org DOI: 10.1888/0333750888/1669 Galaxies at High Redshift Mauro Giavalisco From Encyclopedia of Astronomy & Astrophysics P. Murdin © IOP Publishing Ltd 2006 ISBN: 0333750888 Institute of Physics Publishing Bristol and Philadelphia Downloaded on Thu Mar 02 23:08:45 GMT 2006 [131.215.103.76] Terms and Conditions Galaxies at High Redshift E NCYCLOPEDIA OF A STRONOMY AND A STROPHYSICS Galaxies at High Redshift that is progressively higher for objects that are separated in space by larger distances. If the recession velocity between Galaxies at high REDSHIFT are very distant galaxies and, two objects is small compared with the speed of light, since light propagates through space at a finite speed of its value is directly proportional to the distance between approximately 300 000 km s−1, they appear to an observer them, namely v = H d on the Earth as they were in a very remote past, when r 0 the light departed them, carrying information on their H properties at that time. Observations of objects with very where the constant of proportionality 0 is called the high redshifts play a central role in cosmology because ‘HUBBLE CONSTANT’. For larger recession velocities this they provide insight into the epochs and the mechanisms relation is replaced by a more general one calculated from the theory of general relativity. In each cases, the value of GALAXY FORMATION, if one can reach redshifts that are high H enough to correspond to the cosmic epochs when galaxies of 0 provides the recession velocity of a pair of galaxies were forming their first populations of stars and began to separated by unitary distance, and hence sets the rate of shine light throughout space.
    [Show full text]
  • The Anthropic Principle and Multiple Universe Hypotheses Oren Kreps
    The Anthropic Principle and Multiple Universe Hypotheses Oren Kreps Contents Abstract ........................................................................................................................................... 1 Introduction ..................................................................................................................................... 1 Section 1: The Fine-Tuning Argument and the Anthropic Principle .............................................. 3 The Improbability of a Life-Sustaining Universe ....................................................................... 3 Does God Explain Fine-Tuning? ................................................................................................ 4 The Anthropic Principle .............................................................................................................. 7 The Multiverse Premise ............................................................................................................ 10 Three Classes of Coincidence ................................................................................................... 13 Can The Existence of Sapient Life Justify the Multiverse? ...................................................... 16 How unlikely is fine-tuning? .................................................................................................... 17 Section 2: Multiverse Theories ..................................................................................................... 18 Many universes or all possible
    [Show full text]
  • Year 1 Cosmology Results from the Dark Energy Survey
    Year 1 Cosmology Results from the Dark Energy Survey Elisabeth Krause on behalf of the Dark Energy Survey collaboration TeVPA 2017, Columbus OH Our Simple Universe On large scales, the Universe can be modeled with remarkably few parameters age of the Universe geometry of space density of atoms density of matter amplitude of fluctuations scale dependence of fluctuations [of course, details often not quite as simple] Our Puzzling Universe Ordinary Matter “Dark Energy” accelerates the expansion 5% dominates the total energy density smoothly distributed 25% acceleration first measured by SN 1998 “Dark Matter” 70% Our Puzzling Universe Ordinary Matter “Dark Energy” accelerates the expansion 5% dominates the total energy density smoothly distributed 25% acceleration first measured by SN 1998 “Dark Matter” next frontier: understand cosmological constant Λ: w ≡P/ϱ=-1? 70% magnitude of Λ very surprising dynamic dark energy varying in time and space, w(a)? breakdown of GR? Theoretical Alternatives to Dark Energy Many new DE/modified gravity theories developed over last decades Most can be categorized based on how they break GR: The only local, second-order gravitational field equations that can be derived from a four-dimensional action that is constructed solely from the metric tensor, and admitting Bianchi identities, are GR + Λ. Lovelock’s theorem (1969) [subject to viability conditions] Theoretical Alternatives to Dark Energy Many new DE/modified gravity theories developed over last decades Most can be categorized based on how they break GR: The only local, second-order gravitational field equations that can be derived from a four-dimensional action that is constructed solely from the metric tensor, and admitting Bianchi identities, are GR + Λ.
    [Show full text]
  • Cosmic Microwave Background
    1 29. Cosmic Microwave Background 29. Cosmic Microwave Background Revised August 2019 by D. Scott (U. of British Columbia) and G.F. Smoot (HKUST; Paris U.; UC Berkeley; LBNL). 29.1 Introduction The energy content in electromagnetic radiation from beyond our Galaxy is dominated by the cosmic microwave background (CMB), discovered in 1965 [1]. The spectrum of the CMB is well described by a blackbody function with T = 2.7255 K. This spectral form is a main supporting pillar of the hot Big Bang model for the Universe. The lack of any observed deviations from a 7 blackbody spectrum constrains physical processes over cosmic history at redshifts z ∼< 10 (see earlier versions of this review). Currently the key CMB observable is the angular variation in temperature (or intensity) corre- lations, and to a growing extent polarization [2–4]. Since the first detection of these anisotropies by the Cosmic Background Explorer (COBE) satellite [5], there has been intense activity to map the sky at increasing levels of sensitivity and angular resolution by ground-based and balloon-borne measurements. These were joined in 2003 by the first results from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP)[6], which were improved upon by analyses of data added every 2 years, culminating in the 9-year results [7]. In 2013 we had the first results [8] from the third generation CMB satellite, ESA’s Planck mission [9,10], which were enhanced by results from the 2015 Planck data release [11, 12], and then the final 2018 Planck data release [13, 14]. Additionally, CMB an- isotropies have been extended to smaller angular scales by ground-based experiments, particularly the Atacama Cosmology Telescope (ACT) [15] and the South Pole Telescope (SPT) [16].
    [Show full text]
  • Arxiv:2002.11464V1 [Physics.Gen-Ph] 13 Feb 2020 a Function of the Angles Θ and Φ in the Sky Is Shown in Fig
    Flat Space, Dark Energy, and the Cosmic Microwave Background Kevin Cahill Department of Physics and Astronomy University of New Mexico Albuquerque, New Mexico 87106 (Dated: February 27, 2020) This paper reviews some of the results of the Planck collaboration and shows how to compute the distance from the surface of last scattering, the distance from the farthest object that will ever be observed, and the maximum radius of a density fluctuation in the plasma of the CMB. It then explains how these distances together with well-known astronomical facts imply that space is flat or nearly flat and that dark energy is 69% of the energy of the universe. I. COSMIC MICROWAVE BACKGROUND RADIATION The cosmic microwave background (CMB) was predicted by Gamow in 1948 [1], estimated to be at a temperature of 5 K by Alpher and Herman in 1950 [2], and discovered by Penzias and Wilson in 1965 [3]. It has been observed in increasing detail by Roll and Wilkinson in 1966 [4], by the Cosmic Background Explorer (COBE) collaboration in 1989{1993 [5, 6], by the Wilkinson Microwave Anisotropy Probe (WMAP) collaboration in 2001{2013 [7, 8], and by the Planck collaboration in 2009{2019 [9{12]. The Planck collaboration measured CMB radiation at nine frequencies from 30 to 857 6 GHz by using a satellite at the Lagrange point L2 in the Earth's shadow some 1.5 10 km × farther from the Sun [11, 12]. Their plot of the temperature T (θ; φ) of the CMB radiation as arXiv:2002.11464v1 [physics.gen-ph] 13 Feb 2020 a function of the angles θ and φ in the sky is shown in Fig.
    [Show full text]
  • Lecture 14: the Age of the Universe
    The Age of the Universe One somewhat low-pro¯le but important test of cosmological models is that the age of the universe implied by the models agrees with the age estimated using various methods. Here we'll talk about the age we get from models, and in the next lecture will discuss several observational handles on the true age. For a change of pace, and to give us some practice in evaluating complicated equations, we will start with the equation for the lookback time provided by Hogg in astro-ph/9905116, and see whether the units, limits, etc. make sense. The lookback time from now (z = 0) back to redshift z means the time that would have elapsed on the wristwatch of an observer moving with the Hubble ow between those redshifts. Hogg's expression is: 1 z dz0 tL = 0 0 3 0 2 : (1) H0 Z0 (1 + z ) ­(1 + z ) + ­k(1 + z ) + ­¤ p Here H0 is the current value of the Hubble parameter, and ­, ­k, and ­¤ each indicate their current (z = 0) values. Does this expression behave as it should? See Figure 1 for a graphical representation. As always, we check units ¯rst. Recall that the Hubble parameter has units of inverse time, so the prefactor 1=H0 has units of time. The integral is dimensionless because the redshift is, so indeed the units are correct. Our second easy check is to note that tL must increase with increasing z. Since the integrand is always positive, this is indeed the case. Our third simple check is to note that smaller H0 should imply a larger time back to a given redshift, because H0 = a=a_ today.
    [Show full text]
  • The Hubble Constant
    Astro-2: History of the Universe Lecture 3; April 11 2013 Previously.. On Astro-2 • The universe is much larger than the Milky Way (Gpc vs kpc) • There are billion of galaxies, the Milky Way is average Joe galaxy • Most galaxies can be classified based on their appearance as – Elliptical – Lenticular – Spiral – Irregular • Spirals rotate and have young stars, gas and dust • Ellipticals do not rotate and have old stars, no gas nor dust Previously.. On Astro-2 • It is difficult but very important to figure out the size and distance of things in the universe • One way astronomers do that is by using “standard candles”. • Examples of standard candles are cepheids variable stars and supernovae Two important questions • Are there black holes in galaxies? • What is a black hole? Two important questions • How do we know it? • Exactly in the same way we know the mass of the sun, or the mass of galaxies for that matter! Two important questions • If the universe is homogeneous and isotropic how do stars know that there is a center of a galaxy to orbit around? • It is a matter of scale: • On scale much larger than a Mpc the universe is homogeneous • On scales much smaller than a Mpc the universe is NOT homogenous, there are galaxies, for example. Assignments. Due Friday 4/19 4PM 1. To TA: Universe 24.42 - 24.43 - 24.45 2. On your own: 24.17 thru 24.30 Today.. On Astro-2 1. How far are galaxies? 2. Measuring velocities and “redshifts”. 3. Hubble’s law.
    [Show full text]
  • 22. Big-Bang Cosmology
    1 22. Big-Bang Cosmology 22. Big-Bang Cosmology Revised August 2019 by K.A. Olive (Minnesota U.) and J.A. Peacock (Edinburgh U.). 22.1 Introduction to Standard Big-Bang Model The observed expansion of the Universe [1–3] is a natural (almost inevitable) result of any homogeneous and isotropic cosmological model based on general relativity. However, by itself, the Hubble expansion does not provide sufficient evidence for what we generally refer to as the Big-Bang model of cosmology. While general relativity is in principle capable of describing the cosmology of any given distribution of matter, it is extremely fortunate that our Universe appears to be homogeneous and isotropic on large scales. Together, homogeneity and isotropy allow us to extend the Copernican Principle to the Cosmological Principle, stating that all spatial positions in the Universe are essentially equivalent. The formulation of the Big-Bang model began in the 1940s with the work of George Gamow and his collaborators, Ralph Alpher and Robert Herman. In order to account for the possibility that the abundances of the elements had a cosmological origin, they proposed that the early Universe was once very hot and dense (enough so as to allow for the nucleosynthetic processing of hydrogen), and has subsequently expanded and cooled to its present state [4,5]. In 1948, Alpher and Herman predicted that a direct consequence of this model is the presence of a relic background radiation with a temperature of order a few K [6,7]. Of course this radiation was observed 16 years later as the Cosmic Microwave Background (CMB) [8].
    [Show full text]
  • The Problem of the Age of the Universe and the Earliest Galaxies
    The Problem of the Age of the Universe and the Earliest Galaxies Roger Ellman Abstract A number of years ago the estimates of astronomers and astrophysicists were that the earliest galaxies took about 2½ - 3 billion years to form, that is, that they did not appear until 2.5-3.0 billion years after the Big Bang. Those estimates were based on analysis of the processes involved in star formation and in the aggregation and “clumping” of matter in the early universe. Since then improved equipment and techniques [e.g. Keck and Hubble telescopes and gravitational lensing] have resulted in reports of observation of early galaxies having stars that formed as early as 300 million years after the Big Bang. Such new data has led to the abandonment of the several billion years estimates of the time required for star and galaxy formation; however, an alternative response to the data would be to re-examine the Hubble theory from which the age of the universe and the distance to high redshift objects is determined. Roger Ellman, The-Origin Foundation, Inc. 320 Gemma Circle, Santa Rosa, CA 95404, USA [email protected] http://www.The-Origin.org 1 The Problem of the Age of the Universe and the Earliest Galaxies Roger Ellman Background of the Problem A number of years ago the estimates of astronomers and astrophysicists were that the earliest galaxies took about 2½ - 3 billion years to form, that is, that they did not appear until 2.5-3.0 billion years after the Big Bang. Those estimates were based on analysis of the processes involved in star formation and in the aggregation and “clumping” of matter in the early universe.
    [Show full text]